Why would a morgage company ask about unreimbursed expense on a tax return

Because if your job requires you to spend money in order to get a paycheck, and then do not reimburse you for those expenses; then those expenses have to be subtracted from your wages. If you have any other questions you can reach me at JSchnell@BNCBank.com . -Jeff Schnell NMLS 409473

When looking at your Schedule A of your Federal Tax Returns (assuming you itemize deductions), at the bottom there is a line item 21 for this expense. As Jeff noted, these expenses will be deducted from your Gross Income which can dramatically cut your potential "pre-approved loan amount" down.

Because they will take that amount away from your earnings and qualify you based on the figures after they have been removed.

That amount gets deducted from your gross monthly income. If you've claimed $2000 as your 2106 tax form for 2012 and $1800 for 2013, these amounts would be added together and divided by 24.